1. Technical Field
The present invention relates generally to a semiconductor memory apparatus, and more particularly, to a semiconductor memory apparatus that has an open bit line structure.
2. Related Art
In order to realize highly integrated semiconductor memory apparatuses, semiconductor memory apparatuses have recently been developed having an open bit line structure (6F2).
A folded bit line structure in which bit lines and bit line bars exist in the same cell mat is different from the open bit line structure in which bit lines and bit line bars exist in different cell mats.
FIG. 1 is a view showing the configuration of a conventional semiconductor memory apparatus having an open bit line structure.
Referring to FIG. 1, a semiconductor memory apparatus includes a plurality of cell mats 10-1 and 10-2. The cell mats 10-1 and 10-2 have a plurality of memory cells connected between word lines WL10-WL1i and WL20-WL2i and open bit lines BL0-BLn and /BL0-/BLn. In addition, a sense amplifier block 20 is located between the cell mats 10-1 and 10-2. The bit lines BL0-BLn and /BL0-/BLn, which are connected to the memory cells of the adjoining cell mats 10-1 and 10-2, are commonly connected to their respective sense amplifiers SA of the sense amplifier block 20.
In a recently developed semiconductor memory apparatus having an open bit line structure, the bit lines or bit line bars that are connected to adjoining sense amplifiers, are arranged side by side as shown in FIG. 1. This structure arrangement is called a dual open bit line structure.
In the semiconductor memory apparatus having the dual open bit line structure, when a certain bit line (e.g. BL1) is selected for a sensing operation, a coupling phenomenon occurs between the selected bit line BL1 and an adjacent bit line BL2 connected to the adjoining sense amplifier SA.
Likewise, when a certain bit line bar (e.g. /BL2) is selected, a coupling phenomenon occurs between the selected bit line bar /BL2 and an adjacent bit line bar /BL3 connected to the adjoining sense amplifier SA.
As a result, the semiconductor memory apparatus is likely to malfunction due to the coupling phenomenon and the overall reliability of the semiconductor apparatus may deteriorate.